The presently disclosed embodiments relate generally to a method and system for magnetic actuated mixing which use magnetic particles and electromagnetic field to facilitate milling of different materials. In the present embodiments, the mixing of materials uses the step of milling. Milling is the process of breaking down material and thus involves particle size reduction. The magnetic particles act as milling media. The system further includes non-magnetic abrasive particles in the milling media to facilitate the milling. The present embodiments may be used in many different applications, including for example, preparing toners, inks, wax, pigment dispersions, paints, photoreceptor materials and the like. The present embodiments may be used for any application that requires the preparation of small-sized particles at either the micro or nano scale.
In many batch processes, the milling step is one of most critical steps to determine the overall performance of the process. For example, in applications where small-sized particles are produced, achieving the small scale and uniform distribution of the particles is determined by the milling step.
Improvements on milling methods and systems often generate more complex setups which have their own set of problems, such as increase mechanical maintenance of parts. Recently, acoustic mixing has been used to avoid inefficient milling. As shown in FIG. 1, an acoustic mixing system 30 uses a non-contact mean to provide micro scale mixing 35 within a micro zone of about 50 μm in a closed vessel 40. However, generating the acoustic wave still relies on mechanical resonance as controlled by engineered plates, eccentric weights and springs. Special care and protection of the mechanism to generate mechanical resonance is typically used and any small turbulence may cause catastrophic damage on the system. Therefore, the overall service life is still limited to the effective lifetime of the mechanical components. Thus, such systems are not free of mechanical maintenance. In addition, the acoustic energy decays at distances far away from the source.
There is thus a need for a new and improved milling method and system that overcomes the problems encountered with the conventional systems being used as described above.